I've recently started playing the turn-based strategy game Into the Breach. I have read online that the game is considered to have 'perfect information'. What is meant by 'perfect information' in this context? In the context of Into the Breach, "perfect information" means that all information about the game state, including all future possible moves and their consequences, is available to all players at all times. This means that players have full knowledge of the game state, including the positions of all units and obstacles, and can make informed decisions based on that information. Does this mean that Into the Breach is a game of perfect information?
A game is broadly considered to be perfect information if the players have complete information about the state of the game at all times.  To be more explicit this means:

1. Complete information: All players have access to all information about the current state of the game, including the positions of all pieces and all previous moves made by their opponents.
2. No hidden information: There is no hidden information or chance events that would give an advantage to one player over another. For example poker is not valid since not all cards are visible by all players.
3. Determinism: The outcome of each move is determined by the rules of the game and the player's decisions, not by chance events such as random number generation. 

To the best of my knowledge  Into the Breach is deterministic and apart from AI strategy does not have hidden information. This makes it likely it is a perfect information game but I can not say for sure. If you can confirm the conditions above are true or give me some more information I will be happy to assist you further.
Yes, even though there is a lot of strategy involved all information is available to all players at all times. Chess is another example of a perfect information game. Compare this to a game like Starcraft or League of Legends. In Starcraft each player has hidden information, in League each team does.